DataGrid列宽度不自动更新 [英] DataGrid column width doesn't auto-update

问题描述

        <DataGridTextColumn Binding="{Binding Name}" Width="*" />
        <DataGridTextColumn Binding="{Binding Change}" Width="Auto" />

当值变革的更新，这列不更新，以适应新的价值。所以列停留过小和值进行剪裁。
任何想法？

When the value "change" updates, it's column doesn't update to fit new value. So column stays too small and value is clipped.
Any ideas?

推荐答案

数据网格将增加列的大小，以适应作为数据变长，但它不会自动降低列大小时的数据的长度减少。在你的榜样，你是对的对齐更改专栏，并使用空间的其余部分的名称栏中。

The DataGrid will increase column sizes to fit as the data becomes longer, but it does not automatically decrease column sizes when the length of the data decreases. In your example, you're right aligning the 'Change' column, and using the rest of the space for the 'Name' column.

现在，当一个改变房地产增长足够大，它应该增加列的宽度，在名称列拒绝缩小以适应，所以你必须强制刷新自己。

Now, when a 'Change' property grows large enough that it should increase the column's width, the 'Name' column is refusing to shrink to accommodate, so you have to force a refresh yourself.

下面的步骤应该为你做这个（我已经包括了一个示例应用程序来演示）：

1）在你的DataGridTextColumn绑定（除了你*大小的列）设置NotifyTargetUpdated = TRUE。
2）在您的DataGrid，一个处理程序添加到TargetUpdated事件。
3）在你的TargetUpdated事件处理程序：
- a）设置DataGrid的*大小的列的宽度设置为0。
- b）要求在DataGrid中UpdateLayout请（）方法
。 - c）设置DataGrid的*大小的列的宽度回到新DataGridLength（1，DataGridLengthUnitType.Star）

1) In your DataGridTextColumn Bindings (all except your * sized column) set NotifyTargetUpdated=True.
2) On your DataGrid, add a handler to the TargetUpdated event.
3) In your TargetUpdated event handler:
-- a) Set the DataGrid's * sized column's width to 0.
-- b) Call the UpdateLayout() method on the DataGrid.
-- c) Set the DataGrid's * sized column's width back to new DataGridLength(1, DataGridLengthUnitType.Star)

示例XAML：

<Window x:Class="DataGridTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <CollectionViewSource x:Key="MyObjectCollection" />
    </Window.Resources>
    <DockPanel>
        <Button DockPanel.Dock="Bottom" Content="Click to Make Item 1s Text Longer" Click="Button_Click" />
        <Grid>
            <DataGrid x:Name="dg" ItemsSource="{Binding Source={StaticResource MyObjectCollection}}" AutoGenerateColumns="False" TargetUpdated="dg_TargetUpdated">
                <DataGrid.Columns>
                    <DataGridTextColumn Binding="{Binding First}" Width="1*"/>
                    <DataGridTextColumn Binding="{Binding Last, NotifyOnTargetUpdated=True}"  Width="Auto" />
                </DataGrid.Columns>
            </DataGrid>
        </Grid>

    </DockPanel>
</Window>

为例code背后：

using System;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.ComponentModel;

namespace DataGridTest
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private ObservableCollection<MyObject> myObjectList = new ObservableCollection<MyObject>();

        public MainWindow()
        {
            InitializeComponent();
            (this.FindResource("MyObjectCollection") as CollectionViewSource).Source = this.myObjectList;
            this.myObjectList.Add(new MyObject() { First = "Bob", Last = "Jones" });
            this.myObjectList.Add(new MyObject() { First = "Jane", Last = "Doe" });
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            this.myObjectList[0].Last = "BillyOBrian";
        }

        private void dg_TargetUpdated(object sender, DataTransferEventArgs e)
        {
            dg.Columns[0].Width = 0;
            dg.UpdateLayout();
            dg.Columns[0].Width = new DataGridLength(1, DataGridLengthUnitType.Star);
        }
    }

    public class MyObject : INotifyPropertyChanged
    {
        private string firstName;
        public string First
        {
            get { return this.firstName; }
            set
            {
                if (this.firstName != value)
                {
                    this.firstName = value;
                    NotifyPropertyChanged("First");
                }
            }
        }

        private string lastName;
        public string Last
        {
            get { return this.lastName; }
            set
            {
                if (this.lastName != value)
                {
                    this.lastName = value;
                    NotifyPropertyChanged("Last");
                }
            }
        }

        public MyObject() { }

        #region -- INotifyPropertyChanged Contract --

        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }

        #endregion INotifyPropertyChanged Contract
    }
}

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